in-cyl psi really isn't about air though. do a compression test. with the motor off, you can get like 200 psi per cyl.... its really says nothing about boost.
pipe size does matter to an extent... but a 2.5" charge pipe is pretty much standard on all turbo cars in the 2-500 range.
just remember that air VOLUME (cfm's) is what makes power, not a force of pressure (psi) thats pushing it in.